Synergistic insecticidal compositions



United States Patent SYNERGISTIC INSECTICIDAL COMPOSITIONS Howard A. Jones and John A. Garman, Baltimore, Md., and Berton C. Dickinson, Lyndonville, N.Y., assignors to Food Machinery and Chemical Corporation, New York, N. a corporation of Delaware No Drawing. Original application Mar. 24, 1955, Ser. No. 496,596. Divided and this application Oct. 15, 1958, Ser. No. 767,288

2 Claims. (Cl. 167-22 This invention relates broadly to insecticidal compositions, and more particularly to insecticidal compositions containing an organic carbamate acid derivative and 0,0- dimethyl S-(1,2-dicarbethoxyethyl) dithiophosphate, hereinafter referred to as Malathion. More particularly, this invention relates to synergistic insecticidal compositions of these compounds wherein the insecticidal effectiveness of each component is enhanced by the presence of the other to produce an unexpected combined effect.

When two or more substances in combination show an unexpectedly high activity, as, for instance, insecticidal activity, the resulting phenomenon is called synergism. The mechanism of synergism is by no means understood. It is, in fact, quite probable that it differs with diiferent synergistic combinations. The term synergism can be defined, however, as a cooperative action which is encountered in combinations of two or more biologically active components in which the combined activity of thecomponents when used alone.

The insecticidal activityof the mixed components cannot be predicted from known M [Hahn]) and squash bug (Anasa tristis).

values of the individual components, but is unpredictable.

and depends on the individual activity of neither.

It is an object of this invention to provide insecticidal compositions of enhanced killing power. Another'object" of this invention is to produce novel compositions containing compounds capable of synergizing the knockdownand killing properties of individual toxicants. A further object of this invention is to provide compositions includ ing a relatively toxic phosphorus containing insecticide in which superior insecticidal activity is obtained because of the synergistic eifects, but in which the ultimate toxicity; to warm-blooded animals is greatly reduced because of.

the lower concentrations of the phosphorous compounds required when used in combination with the relatively" less toxic carbamates. Other objects and advantages of the invention will become apparent from the description of the invention set forth below.

According to this invention there are provided syner-.

gistic insecticidal compositions comprising 0,0-dimethyl S-(1,2-dicarbethoxyethyl) dithiophosphate and an organic carbamate ester having the following general formula:

wherein R is selected from the group consisting of phenyl,

furfuryl, benzyl, cyclohexyl and l-naphthyl. These carbamates may be prepared as described in copending application SerfNo. 812,113, filed May 11, 1959.

The synergistic insecticidal compositions of this invention may be used on a wide variety of insect and mite control of truck crop, forage crop and orchard insects.

2,961,370 l atented Nov, a2, 1950 The synergistic compositions of this invention'ea'n'b'; formulated as aqueous emulsions, as dry or wettablepow ders, as solutions or in any other suitable vehicle. The insecticidal compositions can be utilized as sprays, as dusts, as Aerosol mixtures, insecticidal coating compositions, and a residues. In general, they can be applied by methods commonly used for control or eradication of insects, mites and the like. Thus these insecticidal com.- positions canbe formulated with solvents, diluents and carrier media, adhesives, spreading, wetting and emulsifyr ing agents and other ingredients. i

The relative proportions of the active ingredients as well as inert carriers, solvents, dispersants and the like may vary within wide limits.

Thus the relative proportion (ratio) of the Malathion to the carbamate ester can range from 20 parts of the former per 1 part of the latter to 1 part of the former per 40 parts of the latter and preferably about 1 part of the former to about 2 parts of the latter.

The quantities of the component toxicants in the final insecticidal compositions can range from 0.01% to 25.00% for the Malathion and from 0.05% to 50.00%

for the carbamate, and preferably from 0.10% to 10.00%

for the Malathion and from 0.10% to 25.00% for the carbamate. I

The procedures of the testing method are described below. The details of the test experiments including the type of formulation and mode of application or dosing,

" and the species of insects which served as test subjects are given in the examples.

Insects used in the testing included the house fly -(Musca domestica L.), Mexican bean beetle (Epilachna varivestis Muls.), pea aphid (Macrosiphum pisi. [Kl-tb.] two-spotted spider mite (Tetranychus bimacula- {us Harvey), harlequin bug (Murgentia histrionica The test methods, used are described as follows:

DUST TOWER METHOD This general method is described in the following reference, Moore, J. Econ. But. 43, No. 2, 188-190 (1950).

The dusting apparatus consists of a vertical glass cylinder, 34 inches high and 8.5 inches in diameter, into which-the appropriate dust sample is discharged through asmall hole in the center of the cover, by means of a small laboratory duster operating at an air pressure of 40 p.s.i.g. The duster assembly comprises a 10 ml.

beaker, into which the weighed sample is placed, and

fittedwith a rubber stopper through which pass the air inlet and dust outlet tubes, both of which are made of inch diameter copper tubing. At the outer end of the air inlet tube is a trigger valve that serves as a control for dispensing the dust. The inner end of this tube reaches nearly to the bottom of the beaker. The end of it is sealed but, along the sides, seven 0.032 inch holes are drilled at irregular intervals which serve as air inlets. Such an arrangement causes pronounced turbulence of the dust and thus insures exhausting the complete sample from'the beaker. The dust outlet tube forms an arch from the top of the beaker to the top of the glass dusting tower.

After discharge of the sample into the tower, there is allowed a 2-minute settling time before removal of foliage or insects being'treated. A weighed metal plate is placed in the tower eachtime a" test is made, and by weighing the amount'of dust deposited on it, it is then possible to I calculate the amount applied per acre.

. QRQILZ TLEL 5 Slight modifications in this test employed for specific insect species are as noted below.

Two-spotted spider mite-In tests on two-spotted mites, the mites were confined to the uppersurfaces of placed. At the end of 24 hours the treated leaves were removed and fresh untreated leaves were introduced into the dishes. Mortality counts were taken after the bugs had been on the untreated leaves for 24 hours.

potted bean plants by a Tanglefoot ring. The bean 5 Mexican bean beetle.--In tests using this insect, bean plants were placed in the glass tower and the mites foliage was dusted then infested with fourth instar Mexidirect-dusted. Mortality readings were taken in 24 can bean beetle larvae. These were allowed to feed for hours. Only adult mites were used in determining mor- 24 hours, then treated foliage was replaced with untreated. tality counts. Mortality records were made at 48 hours.

Squash bug.--For this test squash leaves were collected 10 Pea aphid.-Pea plants were infested with pea aphids in the field and the cut ends of the stem were wrapped and direct-dusted. Mortality readings were taken at in moist cotton. Individual leaves were then placed in 24 hours.

3.5 inch Petri dishes and dusted as described above. Each Harlequin bug-The foliage was dusted, then infested treated leaf was then infested with 10 last instar squash with harlequin bugs. Mortality counts were taken in 24 hug nymphs .and the covers of the Petri dishes were re- 15 hours.

Table I Carbamate Phosphate Rate Test Test Subject Mortality Dust Dust (Lbs/A.) Method (Percent) R4 Cone. Name C0110.

(Percent) (Percent) Dodecyl 1 9.7 D st Two-Spotted 1 Tower Spider Mite Malathion 5 10.0 0 .--.do..- 22 Do 1 --.d0 05 11.2 do .do 72 3-Methoxy- 1 8.0 do Mexican Bean propyl. Beetle.

Malathion 0.5 10.7 do .do 0 0--.-.- 0.15 10.2 d0 cl o so 9.6 ...do Two-Spotted 2 Spider Mite. Malathlon 0.5 6.1 do- -do.-- 10 Do 1 -.do- 0.5 9.7 do do 100 2-Chlor0- 1 7.5 -.-do d0 7 phenyl.

7.2 do d0 41 Do 4.3 do d0 51 Furfuryl 9.4 .do Mexican Bean 5 Beetle 11.3 Do 11.0 100 Do 11.5 9 9.7 82 Do 10.2 100 Do 10.7 2

10.0 22 Do 6.7 do. 100 Do..'.,.'..-. 19. 0 Harlequin Bug 0 17.6 ....do 30 Do... 19.2 do .d0 100 Oyclohexyl... 14.2 do Two-Spotted 0 Spider Mite. 10.7 -d0 "do 9 12.0 d 100 12.3 1 Malathion 0. 25 13. 2 01 o 0.25 12.0 100 31.3 do Squash Bug 0 Malathion 0.25 29.2 --.d0 do ..d0 0.25 27.0 d 100 40.4 0 Malathlon 0. 25 46. 6 0 o 0.25 47.4

............. 26.5 do 'lwoSpotted 10 Spider Mite. Malathion 0.25 24.3 .d0 d0 58 do 0.25 21.4 do do 93 7.2 410.-...- Two-Spotted 0 Spider Mite. Malnthlon 0.26 8.0 do .-do 25 d0 0.25 5.3 .do d0 formula:

wherein R is selected from the group consisting of phenyl, furfuryl, benzyl, cyclohexyl and l-naphthyl, said components being present in the ratio of about 2 parts of said carbamate ester to about 1 part of said dithiophosphate.

2. A method of killing insects which comprises applying to the insects and their habitat synergistic insecticidal compositions comprising 0,0-din1ethyl S-(l,2-dicarbeth- 5? oxyethyl) dithiophosphate and an organic carbamate ester having the following general formula:

NOOO wherein R is selected from the group consisting of phenyl, furfuryl, benzyl, cyclohexyl and l-naphthyl, said components being present in the ratio of about 2 parts of said carbamate ester to about 1 part of said dithiophosphate.

References Cited in the file of this patent UNITED STATES PATENTS 2,503,390 Jelinek Apr. 11, 1950 OTHER REFERENCES King: U.S.D.A. Handbook No. 69, May 1954, pp. -108.

Sharp: Agr. News Letter, Jan-Feb. 1952, pp. 1-3.

Roark: US. Dept. Agr. Bull. E-344 (May 1935), pp. 2-6.

Frear: Chem. of the Pesticides, 3rd ed., January 1955, pp. 73-91.

Gysin May 25, 1954 V 

2. A METHOD OF KILLING INSECTS WHICH COMPRISES APPLYING TO THE INSECTS AND THEIR HABITAT SYNERGISTIC INSECTICIDAL COMPOSITIONS COMPRISING O,O-DIMETHYL S-(1,2-DICARBETHOXYETHYL) DITHIOPHOSPHATE AND AN ORGANIC CARBAMATE ESTER HAVING THE FOLLOWING GENERAL FORMULA: 